I created my own station for the ride as well. The entire queue line is indoors, The Double sided lockers are located at the 2nd floor, at the right. The queue ends to the dual sided lockers that leads to the waiting area for a pre show.

Thank you. From recollection of around 2018 and prior I never recall seeing the arches barricaded at KI.  To me it looks trashy like some of the legacy six flags parks Ive been to. I agree that Canada has the most pleasing appearance of the three, but that bridge is a pain to cross. KD's version is surpassed by ours with our refined look with the decorative white pilasters vs KD's fence.  However, this is subjective.

I have been wondering how a queue could work for a Vortex replacement and I mocked up a sorta idea of a queue line with a double sided locker system and metal detectors (like Siren's Curse). The station of the coaster would be higher than usual allowing for a bunch of open space underneath the station that would be used for the double sided lockers, the exit gift shop, on ride photo booth, and a merged queue that would also feature a "pre-show" for the ride. The coaster model I have is a modern Vekoma launch.    

My best guess is that the open arch is to allow light and a view out on the fountain from the control room, while the closed arch(es) are where the water pump mechanism(s) live and don't need the light or the view. The 2011 Google Street View capture actually shows all three arches being open. You can see the evolution between the three Royal Fountains below. The aforementioned 2011 Google Street View capture from Kings Island. The 2015 capture from Kings Dominion. You can see how their fountain pump house was different than Kings Island's as Taft and their park designers refined International Street for their second park. Lastly, here's the same view from Canada's Wonderland. Their pump house is located under the bridge in front of Wonder Mountain and (I believe) services both the Royal Fountain and the pools at the bottom of Wonder Mountain. I don't know where the access door is for this fountain, but it is certainly the grandest of the three versions of International Street.

I don't know why, but when I saw this picture I thought of Kitty Claws at Holiday World 😂